206-00-3 Brake System — General Information 206-00-3
DIAGNOSIS AND TESTING
E1092 EN 07/2001 2002 Bantam
Brake System
The brakes system operates by transferring effort
applied to the brake pedal by the driver to the
brakes at each wheel.
The braking effort is distributed to each wheel,
using a hydraulic system. The system is assisted
using a vacuum brake booster that reduces pedal
effort and increases hydraulic pressure.
The parking brake operates on the rear wheels
and is applied using a hand-operated control.
Inspection and Verification
NOTE: Before carrying out any diagnosis, make
sure that the brake system-warning indicator is
functional.
1. Verify the customer concern.
2. Visually inspect for obvious signs of
mechanical damage.
Visual Inspection Chart
Mechanical
• Tyre pressure
• Wheels and tyres
• Fluid leak from brake line(s)
3. If an obvious cause for an observed or
reported concern is found, correct the case (if
possible) before proceeding to the next step.
4. If the cause if not visually evident, verify the
symptom and refer to the Symptom Chart.
Road Test
Perform a road test to compare actual vehicle
braking performance with the performance
standards expected by the driver. The ability of
the test driver to make valid comparisons and
detect performance deficiencies will depend on
experience.
The driver should have a thorough knowledge of
the brake system operation and accepted general
performance guidelines to make good
comparisons and detect performance concerns.
An experienced technician will always establish a
route that will be used for all brake diagnosis
road tests. The road selected will be reasonably
smooth and level. Gravel or bumpy roads are not
suitable because the surface does not allow the
tyres to grip the road equally. Crowned roads
should be avoided because of the large amount
of weight shifted to the low set of wheels on this
type of road. Once the route is established and
consistently used, the road surface variable can
be eliminated from the test results.
Before a road test, get a complete description of
the customer concerns or suspected condition.
From the description, the technician will be able
to match possible causes with symptoms. Certain
components will be identified, as possible
sources while others will be eliminated by the
evidence. More importantly, the customer
description can reveal unsafe conditions, which
should be checked or corrected before a road
test. The description will also help form the basic
approach to the road test by narrowing the
concern to specific components, vehicle speed or
conditions.
Begin the road test with a general brake
performance check. Using the description of the
concern, test the brakes at different vehicle
speeds using both light and heavy pedal
pressure. Determine if the concern is in the front
or rear braking system. First use the foot brake
and then the parking brake. If the condition (i.e.
pull, vibration, pulsation) occurs only on operation
of the parking brake, the concern is in the rear
brake system. If the condition occurs when the
foot brake is depressed, the concern is in the
front brake system.
Avoid locking the brakes and sliding the tyres.
This condition will not indicate brake efficiency. A
heavily braked but turning wheel will stop the
vehicle in a shorter distance than locked wheels.
If the concern becomes evident during this check,
make sure it fits the description given before the
road test. If the concern is not evident, attempt to
duplicate the condition using the information from
the description.
If a concern exists, use the Brake System Symp-
tom Chart in order to isolate it to a specific sub-
system and condition description. From this de-
scription, a list of possible sources can be used
to further narrow the cause to a specific compo-
nent or condition.
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